Sew the front

• Cut the lace about 8 inches and gather it. Make two.
• Put gathered lace between the front-side and the front and sew.
  Make the both ends of the lace diminish.
• I recommend pre-gathered lace.
• Stitch zigzag or lock the seam allowance and stitch from outside.

To see close-up picture.

Sew the crotch

• Put the front between two pieces of crotch and sew.
• Turn inside out the crotch and sew to the back cloth.
  (If you feel difficulty, observe your panty. It's easy!)
• Stitch from outside.
• Sew up the front and back at sides.

Outside
Inside.

Waist and hem

• Make zigzag stitches on the seam allowance.
• Hold the allowance of the waist and stitch.
  Unseam 1/4 inch. For to pass the elastic.
• Also stitch 0.15 inches from the hem.
• Sew the lace to the hem of groins. Unseam 1/4 inch too.